It seems CREATE AGGREGATE was expanded in 9.6 to support parallelization of aggregate functions using transitions, with the addition of serialfunc and deserialfunc to the aggregate definitions.
https://www.postgresql.org/docs/10/static/sql-createaggregate.html I was looking at the PostgreSQL 10 source code for some example usages of this and was hoping that array_agg and string_agg would support the feature. At a cursory glance, it seems they do not use this. Examples I see that do support it are the average and standard deviation functions. Is there a reason for this or it just wasn't gotten to? Thanks, Regina -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers